cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration sched/sched_setscheduler.c -o sched/sched_setscheduler -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
sched/sched_setscheduler.c: In function ‘main’:
sched/sched_setscheduler.c:10:22: error: implicit declaration of function ‘sched_getscheduler’ [-Wimplicit-function-declaration]
   10 |         int policy = sched_getscheduler(0);
      |                      ^~~~~~~~~~~~~~~~~~
sched/sched_setscheduler.c:18:14: error: implicit declaration of function ‘sched_getparam’ [-Wimplicit-function-declaration]
   18 |         if ( sched_getparam(0, &params) < 0 )
      |              ^~~~~~~~~~~~~~
sched/sched_setscheduler.c:24:14: error: implicit declaration of function ‘sched_setscheduler’ [-Wimplicit-function-declaration]
   24 |         if ( sched_setscheduler(0, policy, &params) < 0 )
      |              ^~~~~~~~~~~~~~~~~~